S321 Stainless Steel Pipe

1. Standard: ASTM A312, ASME SA312
2. Size: 1/2''~48''
3. Thickness: SCH5~SCHXXS
4. Service: Cutting, Welding, Fabricated, Customized

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Product Introduction

S321 stainless steel pipe belongs to the category of austenitic stainless steel pipes. Its core feature is the addition of titanium (Ti) element on the basis of S304 stainless steel. Through the combination of titanium and carbon, the precipitation of carbides at grain boundaries is reduced, thereby significantly improving the resistance to intergranular corrosion. HT PIPE is a SS321 Pipe supplier with 15+ export experience. Contact us for more information and quotes for free!

We offers S321 stainless steel in a variety of forms, including:

Bar
Wire
Sheet
Plate
Forgings
Pipe fittings
Flanges
Seamless & Welded pipe
Seamless Tube & Welded tube
Weld Rod

ASTM A312 TP 321 Stainless Steel Seamless Pipe Specification

ASTM / ASME Name	ASTM A 312 ASME SA 312 / ASTM A 213 ASME SA 213
Dimensions Standard	ASTM, ASME and API
Stainless Steel 321 Seamless Pipes Size Range	0.5″ NB – 16″ NB
OD Sizes	0.5″NB TO 30″NB IN
Specialized in	Large Diameter Size
Schedule	SCH20, SCH30, SCH40, STD, SCH80, XS, SCH60, SCH80, SCH120, SCH140, SCH160, XXS
Frequently Used Type	Seamless
Available Pipes Form	Round
Length	Single Random, Double Random & Cut Length.
End Finishing	Plain End, Beveled End, Treaded End

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Physical properties of S321 pipe

Density: Approximately 7.93g/cm ³, close to the density of most austenitic stainless steels, it is a key reference parameter for calculating pipe weight and designing pipeline load-bearing structures.

Melting point: The range is 1398 ℃ -1454 ℃, and the higher melting point allows S321 pipe to be used for a long time under medium and high temperature conditions, such as industrial pipeline transportation scenarios at 400 ℃ -650 ℃.

Thermal expansion coefficient: The linear expansion coefficient in the range of 20 ℃ -100 ℃ is about 16.9 × 10 ⁻⁶/℃. The temperature range between 20 ℃ and 500 ℃ is approximately 18.3 × 10 ⁻⁶/℃, and stable thermal expansion performance can reduce pipeline deformation or interface leakage caused by temperature changes.

Thermal conductivity: About 16.3W/(m · K) at 20 ℃ about 22.2W/(m · K) at 500 ℃. The lower thermal conductivity allows the pipe to reduce heat loss in piping systems with high insulation requirements.

Hardness: In annealed state, Brinell hardness (HB) ≤ 187, Rockwell hardness (HRB) ≤ 90. After cold processing, the hardness will increase, with Brinell hardness (HB) reaching 200-230 and Rockwell hardness (HRB) reaching 95-105. Different hardness states are suitable for pipeline scenarios with different strength requirements.

Specification parameters of S321 pipe

ss321 tube Outer diameter range

Small caliber pipes (outer diameter 6mm-50mm): Mostly cold drawn and suitable for precision equipment pipelines and instrument connecting pipes.
Medium caliber tube (outer diameter 51mm-219mm): Suitable for both hot and cold rolling, suitable for industrial medium transportation and heat exchanger tube bundles.
Large diameter pipe (outer diameter 220mm-630mm): Mainly hot-rolled, suitable for large storage tank inlet and outlet, municipal engineering pipelines.

stainless steel 321 pipe Wall thickness range

Depending on the outer diameter, the wall thickness is generally 0.8mm-20mm. Common wall thickness series are divided into Sch 5s, Sch 10s, Sch 20s, Sch 40s, Sch 80s, etc. according to standards such as ANSI B36.10. Among them, Sch 40s is a commonly used specification and is suitable for most industrial scenarios.

s321 tube Length range

Fixed length: Common sizes are 6m, 9m, and 12m. Customized fixed length pipes ranging from 3mm to 18m can be made according to customer needs, taking into account transportation convenience.

Non fixed length: Generally ranging from 3m-12m, with a length deviation of ± 50mm allowed, suitable for scenarios where there are no strict requirements for length.

uns s32100 pipe Tolerance standard

Outer diameter tolerance: ± 0.1mm - ± 0.3mm for cold drawn pipes and ± 0.5mm - ± 1.0mm for hot-rolled pipes, in accordance with ASTM A312 or GB/T 14976 standards.

Wall thickness tolerance: ± 0.05mm - ± 0.15mm for cold drawn pipes and ± 10% - ± 15% for hot-rolled pipes (relative to nominal wall thickness).
Length tolerance: ± 10mm for fixed length pipes and -50mm -+100mm for non fixed length pipes.

s32100 tube Connection methods

Common connection methods include welding (butt welding, socket welding), threaded connection (internal thread, external thread), flange connection (flat welding flange, butt welding flange).